1. Field of the Invention
This invention relates in general to semiconductor devices and more specifically to stacking multiple semiconductor devices.
2. Description of the Related Art
Conventional through-silicon-via (TSV) plugs for die stacking are formed at the single wafer level. The die are then interconnected into a stack with an interconnection at each wafer or die face. Height is added to the stack as a result of the bump standoff height at each die-to-die transition. Electrically, each interface contributes to reflections and added impedance which together reduce the high frequency signal integrity. Additionally, it is always desirable to dissipate heat from semiconductor devices to achieve smaller device sizes and higher frequency operation. In particular, stacked die generate heat in a small volume requiring additional thermal paths for heat dissipation.
The use of the same reference symbols in different drawings indicates identical items unless otherwise noted. The features shown in the Figures are not necessarily drawn to scale.